In the field of natural gas gathering and transportation engineering, it is well known that some gas sources may have a pressure lower than the pressure of gas pipeline network, which causes the gas thereof fail to enter the gas pipeline network, whilst the pressure of other gas sources in the same area is higher than the pressure of gas pipeline network. For a long time, people have been involved in development of techniques which use residual pressure of high-pressure gas sources to boost pressure of the low-pressure gas, so that the pressure of the high-pressure gas source and the low-pressure gas source can achieve the pressure of the gas pipeline network simultaneously and enter the gas pipeline network. A commonly used technique is high-pressure gas injection. However, this technique has a very low efficiency of utilization of high-pressure gas pressure. Several times or even dozens of times of the high-pressure gas will be necessary to inject a part of low-pressure gas.